LAUSR

Plasma and erythrocyte PUFAs are useful in clinical practice to optimize the parenteral nutrition therapy. The aim of this study was the definition of pediatric PUFAs reference ranges to follow-up patients with IICB. We validated a method to quantify, in plasma and erythrocyte membranes, glycerophospholipids PUFAs by gas chromatography coupled with the highly specific Mass spectrometer. The analyzed PUFAs are only those metabolized by liver: no interferences by oral nor parenteral nutrition are expected. Metabolically significative PUFAs were selected for analysis: ARA (ω6), EPA and DHA (ω3) were quantified because they are precursors of important mediators of inflammation, while Mead Acid determination is useful to calculate the ratio ARA (ω6)/ Mead (ω9), a known marker of essential fatty acid deficiency. We quantified these PUFAs in healthy pediatric subjects to build reference ranges. A pilot study was performed to compare PUFAs of two groups of pediatric patients with IICB (group A fed with Clinoleic® and group B with SMOF®) with reference ranges. Pediatric reference ranges of PUFAs were proposed. A good correlation between plasma and erythrocyte results was shown for the ratio ARA/(EPA+DHA), (R2=0.941). PUFAs assessment is highly recommended in plasma rather than in erythrocytes because plasma is less prone to peroxidation artifacts. Our fast method can offer an accurate, specific and easy-to-handle PUFAs analysis and a useful marker of w6/w3 balance in tissues for routine clinical practice. This work could be a step towards standardization of routine determination of PUFAs.